Method of starting a combined wire-drawing,annealing and spooling operation

ABSTRACT

A METHOD OF AND A DEVICE FOR STARTING A COMBINED WIRE-DRAWING, ANNEALING AND SPOOLING OPERATION IN WHICH THE WIRE FEEDING CAPSTAN IS DRIVEN BY THE ANNEALER TO ACCELERATE THE SPEED OF THE WIRE INDEPENDENTLY OF THE ACCELERATION OF THE ROTATION OF THE DRAWING WHEELS OF THE DRAWING MACHINE.   D R A W I N G

g- 1972 A. s. RIEKKINEN 3,532,723

METHOD OF STARTING A COMBINED WIREDRAWING, ANNEALING AND SPOOLING OPERATION- 2 Sheets-Sheet 1 Filed Jan" 20, 1970 g- 3, 1972 A. s. RIEKKINEN 3,682,723

AWING, ANNEALING A COMBINED WIRE-DR AND SPOOLING OPERATI METHOD OF STARTING 2 Sheets-Shoot 2 Filed Jan. 20, 1.970

US. Cl. 148-156 United States Patent 3,682,723 METHOD OF STARTING A COMBINED WIRE- DRAWING, ANNEALING AND SPOOLING OPERATION Asko Sakari Riekkinen, Kaunianen, Finland, assignor to 0y Nokia AB, Helsinki, Finland Filed Jan. 20, 1970, Ser. No. 4,263 Int. Cl. C21d 9/52 3 Claims ABSTRACT OF THE DISCLOSURE A method of and a device for starting a combined wire-drawing, annealing and spooling operation in which the wire feeding capstan is driven by the annealer to accelerate the speed of the wire independently of the acceleration of the rotation of the drawing wheels of the drawing machine.

The present invention concerns a method of starting a combined wire-drawing, annealing and spooling operation, in which the wire is passed through a drawing machine by means of drawing wheels and through an annealer, in which the wire is charged with electric current by means of contact wheels contacting the wire in order to anneal the wire, whereafter the wire is wound on a reel in a spooler. The invention also concerns an annealer for carrying out this method.

In conventional annealers the contact wheels are connected with one another by means of a transmission belt or they are rotated by the means of separate inductive couplings. The annealer is usually placed immediately behind the drawing machine. From the annealer the wire mostly proceeds to the spooler directly or through a plastics extrusion press. The difiiculty nowadays is the I synchronizing of the annealer to the speed of the drawing machine, which synchronization is necessary in order to prevent the wire from stretching or breaking in the case of thin wires (eg of 0.3 to 0.8 mm. diameters). The drawing machine starts at a fast accelerating speed due to its powerful motor, whereas the spooler starts at a rather moderate speed on account of the very heavily weight of the reels. The synchronizing methods mostly used are the following:

(1) coupling the annealer mechanically to the drawing machine by means of a power transmission belt,

(2) allowing the wire to synchronize the speed of the annealer with the speed of the wire,

(3) placing a separate wire accumulator between the drawing machine and the annealer, which latter is provided with a potentiometer that passes a signal to the driving motor of the annealer.

The first method causes starting difiiculties. As the reel in the spooler accelerates gradually towards top speed while the drawing machine normally starts with a rather fast accelerating speed, the drawing machine has to be equipped with a driving motor of a type, the speed of which can be accelerated slowly. Due to the rather great power required for the purpose (50-100 kw.) driving motors of this type are very expensive.

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The second method used, in which the wire itself synchronizes the contact wheels with the right speed, has also its drawbacks. The contact wheels are charged with electric current by means of contact brushes. As rather strong currents are required, several brushes are necessary. This creates friction retarding the rotation of the contact wheels, that has to be eliminated for instance by means of inductive coupling. As the compensating moment is rather great in comparison with the tension tolerated by the wire, the adjustment calls for great precision and is for this reason very difficult to carry out.

When using the third method, the accumulator produces a certain degree of tension in the Wire. As a result of this tension, the wire leaves the drawing machine at the nominal speed of the machine. In order to get a perfect start, the accumulators accumulation capacity ought to be large in order to be capable of accumulating all the wire produced during the starting period. This is difficult to accomplish.

The object of the present invention is to obtain such a starting method, that will permit the annealer to be connected to a drawing machine of normal construction Without special adjustments having to be made to the driving motor of the drawing machine and by means of which the combined machines may be started without difliculties.

The said object is achieved according to the present invention by a method characterized in that the Wire during the starting phase is allowed to slide on the drawing wheels of the drawing machine, that the sliding of the wire is controlled by a capstan, which is connected in driving engagement with the contact wheels, and that the wire-feeding speed of said capstan is increased to the wire-feeding speed of the drawing machine with an acceleration not exceeding the acceleration of the spooling speed of the reel in the spooler.

The method and the annealer according to the present invention offer the following advantages:

(1) The driving motor of the drawing machine may be an ordinary squirrel cage motor, which means a considerable saving of expenses. The power required by the capstan connected to the annnealer is only a fractional part of the total power of the drawing machine, for which reason the adjustable speed driving motor required for the anealer may be a small-sized one and consequently obtainable at a favourable price.

(2) The annealer can be attached to the drawing machine quickly and easily without the trouble and expense caused by the mounting of a transmission belt. Only a tachometer generator needs to be coupled to the drawing machine.

(3) By using the method according to the present invention the wire will be prevented from too heavy tensile strain, which constitutes a guarantee for the quality and uniform annealing of the wire.

(4) The mounting of the annealer is a simple operation. The device may be mounted to conform to drawing machine operations of the most different kinds.

The invention is described more in detail hereinafter,

reference being made to the accompanying drawings, in which J r r 3,682,723

FIG. 1 shows a side view of a first embodiment of an apparatus used for the application of the method according to the invention,

FIG. 2 shows the apparatus viewed from above,

FIG. 3 shows a side view of a second apparatus embodiment and bFIG. 4 shows the arrangement of FIG. 3 viewed from a ove.

In the drawing, reference numeral 1 shows a drawing machine, 2 shows an annealer and 3 a spooler. The wire 4 to be drawn and annealed is supplied from a reel 5 into the drawing machine 1, in which the wire is wound round usual drawing wheels 6 and guided through drawing dies (not. shown). The driving motor for the drawing wheels vice 15 arranged between the contact wheels 8 and 9,

whereby after-heating is carried out between contact wheels 9 and 10. The drawn wire 4 is after leaving the drawing machine wound a few turns around the pulley 14 and contact wheel8 and guided onto the annealing device 15, around contact wheel 9, out from the annealing device and further over intermediate wheels 16 to contact Wheel and leaves finally the annealer. The contact wheels 8, 9 and 10 are connected to an electric source (not shown) in such a way, that the electric current passing through the wire heats in the ordinary waythe wire to annealing temperature.

On leaving the annealer 2 the annealed wire 4 passes on to a wire accumulator 17, which controls the reeling speed of the spooler 3. The spooler comprises a reel 18, around which the wire is'wound, and a driving motor 19 rotating the reel.

The wire 4 is wound around the drawing wheels 6 in the drawing machine in such a way, that the friction between said wheels and the wire is not alone suflicient to pull the wire at full drawing speed through the drawing machine, but the wire slides on the drawing wheels 6 as they are rotated by the driving motor 7. i v i The wire 4, on the other hand, is wound round the pulley 14 and contact wheel 8 in such a manner,'that the wire is prevented from sliding on the pulley'and the contact wheel. The pulley and the contact wheel are consequently acting as a capstan, which causes an extra pull on the wire in the drawing machine. This extra pull combined with the sliding, friction in the drawing machine is sufiicient for pulling the wire through the drawing machine at the speed of the capstan. Consequently the capstan controls the sliding of the wire on the drawing wheels as well as the speed at which the wire is being fed forwards. The capstan is not, however, alone capable of pulling the wire through the drawing machine.

speed of the annealer is increasing, the relative sliding of the wire in the drawing machine is continuously'diminishing, so that the sliding has substantially stopped when the annealer has reached top speed.

The speed of the annealer is raised so as to be near the nominal speed of the drawing machine. This adjustment is effected with the aid of a tachometer generator 20, which tests the rotative velocity of the driving motor 7 of the drawing machine and sends a corresponding adjustment signal to the driving motor 12 as is shown by the dash line 21. By this means it is possible to maintain a small speed difference between the drawing machine and the annealer, which serves'las a guarantee, that no tension will develop, which might cause stretching of the wire.

Although the capstan is presented above as being a combination of the pulley 14 and the wheel 8,*it is evident that the contact wheel'8 may also alone operate as a capstan. I H 7 In the embodiment according to FIGS. 1 and 2 the annealer 2 itself is provided with a special capstan construction 14, 8. However, it is also possible to carry out the invention by utilizing a normal pull out capstan which is generally available in a conventional wire-drawing device. FIGS. 3 and 4 illustrate such an embodiment. Corresponding parts have been indicated by the same reference numerals.

The drawing device 1 is of conventionaltype and includes a pull out capstan 22, which is disconnected from the power transmission gearing of thedrawing device which is driven by the electric motor 7. Instead the axis 23 of the capstan is rotated by the electric motor 12 of the annealer 2 by means of power transmission belts 24 and 25. The belt 25 connects a wheel 26 on the axis of themotor 7 with a wheel 27 rotating apulley 28 for the wire 4 entering into the annealer. The contact wheels 8, 9 of the annealer are driven by said motor 7 by means of a power transmission gearing not shown.

The wire 4 enteringthe drawing device is guided around the drawing wheels 6 and the capstan 22' and further guided by the pulley 28into the annealer in which the wire is treated in the same manner as described above in connection with the first embodiment.

When the motors 7 and 12 are started at the same time, the capstan 22 accelerates synchronously with the acceleration of the contact wheels of the annealer independently of the much faster acceleration of the drawing wheels 6 of the drawing device. During this acceleration of the capstan the wire slides on the drawing wheels but is pulled through the drawing device with, an increasing speed by the capstan. Thus the operationof the drawing wheels 6, the capstan 22 and the contact wheels 8, 9 is similar tothe operation of the drawing wheels 6, the capstan 14, 8 and the contact wheels 8, 9, 10 of the first em- When starting the apparatus, the motors 7, 12 of the drawing machine and the annealer are started simultaneously. The drawing machine accelerates quickly to its nominal speed level, whereas the speed of the spooler accelerates more slowly for the reasons explained above.

The speed of the annealer is therefore raised towards, top speed by a predetermined gradual acceleration, which is adjusted in advance by means of the control unit 13. The control unit regulates thus the acceleration of the rotative velocity of the annealer driving motor 12 so thatthe rotaspeed. During the acceleration period the wire slides on the drawing wheels in the drawing machine. Because the capstans 8, 14 is pulling the wire faster and faster as the bodiment during the acceleration step as well as during operation at-full speed. i

In the embodiment according to FIGS. 3 and 4 it is :further possible to connect the axis of the capstan 22 to the power transmission gearing of the drawing device 1 by means of a sliding coupling, e.g. an induction coupling. In this waythe driving of the capstan by means of the motor 12 of the annealer 2 is promoted by the motor 7 of the drawing device. However,'the capstan still accelerates in accordance with the acceleration of the contact wheels of the annealer independently of the acceleration of the drawing device.

What I claim is: v

1. In a method of starting a combined wire-drawing, annealing and spooli ng operation, including passing a wire sequentially through a drawingmachine by means of drawing wheels driven by a first electric motor, and through an annealer, charging theIfwire in said annealer with an'electr'ical current through contact wheels driven by a second electric motor and contacting the wire so as to anneal the wire, and winding the wire on a reel in a spooler, the improvement comprising; sliding the wire during the starting phase relative to the drawing wheels of the drawing machine, concurrently controlling the sliding of the wire by a capstan connected in mechanical driving engagement with said second motor for the contact wheels, and increasing the wire-feeding speed of said capstan to the wire-feeding speed of the drawing machine at an acceleration rate not exceeding the acceleration of the spooling speed of the reel in the spooler.

2. An improvement as claimed in claim 1, comprising forming the capstan by the contact wheel at the inlet end of the annealer.

3. An improvement as claimed in claim 1, comprising forming the capstan by a pull-out capstan of the draw- References Cited UNITED STATES PATENTS 3/1952 OGrady 148-156 RIOHA-RD O. DEAN, Primary Examiner US. Cl. X.R. 148-154 

